Loss of cooling or heating in heating and ventilating systems due to condensate drain blockages and subsequent tripping of a condensate switch is a regular occurrence during operation. Often this results in a service call and onsite diagnostics for what is a simple and usually easily resolved problem. Remediation is possible by a low-level technician or the home owner, especially if intervention is early. Often in the initial stages of a condensate drain blockage interruptions are cyclic as the drain is slow, but not completely blocked.
Prior solutions include direct monitoring of the condensate switch and alarms are available, but require additional hardware to be installed, which is beyond the capabilities of a typical homeowner and therefore means increased expense for the added protection that switch monitoring can provide.
The prior art consists of electro-mechanical or electronic switches which are added to the condensate pan or drain tube, and interrupt the signal from the thermostat if a high-water condition is detected in either. These switches can be included in a circuit containing an audible alarm which is activated if a flooded pan is detected.
The prior art also discloses diagnostic systems which monitor the condition of a variety of components in a heating, ventilation, and air conditioning (HVAC) system by monitoring the control line current to one or more of the components.